Technical Information

1 Short Application Note on Sheet Resistance, Ohms-Per-Square, and the Calculation of Resistivity or Thickness

2 Basic information regarding how to make four point probe measurements using Jandel resistivity test equipment.

3 Four Point Probe Theory - A helpful article

4 Four Point Probe Equations - A helpful article from the      University of Illinois - Urbana/Champaign

5 Understanding volume resistivity measurements and converting between ohms-per-square (sheet resistance) and ohms-cm (volume resistivity)

6 Sample Size Requirements and Correction Factors Some questions and answers from Jandel Engineering Ltd.

7 Haldor Topsoe Technical Documents Regarding Correction Factors Correction Factor for various material shapes and sizes

8 1964 National Bureau of Standards Technical Note 199, "Correction Factor Tables for Four-Point Probe Resistivity Measurements on Thin, Circular Semiconductor Samples"

9 Finite-Size Corrections for 4-Point Probe Measurements, by J. R. Senna, Instituto Nacional de Pesquisas Espaciais (INPE), Brasil

10 Questions and answers re: resistivity & resistance, sheet resistance, volume resistivity, surface resistivity by John Clark of Jandel Engineering

11 Q & A regarding the use of Jandel Resistivity Measurement equipment by Pete Clark of Jandel Engineering

12 Four-Point Probe Theory of Operation from the University of California, Berkeley, EECS web site (PDF file)

13 A table of suggested probe tip specifications for various silicon wafer types.

14 A table of common four point probe tip radii and spacings

15 Osmium alloy tips versus tungsten carbide tips

16 Square array versus linear array four point probe

17 Reversing current to check the validity of a 4 point probe measurement

18 Determining the best choice of probe tip specifications (tip spacing, spring loads, material, radii) for a given material.

19 What is the expected life of a Jandel Four Point Probe Head?

20 Jandel FAQ

Hall Effect Measurement Technical info:

21 Wikipedia article regarding the Hall Effect

22 Wikipedia article regarding the Van der Pauw method

23 NIST web page regarding the theory and implementation of the Hall Effect Measurement technique

 

Common Four Point Probe Tip Radii and Spacings

Jandel Table of Typical Needle Spacings

 

Common Needle Spacings:

 

American

English (Imperial)

Metric

Sometimes expressed as

25 mils

0.025"

0.635mm

 
 
 

0.636mm

1/(5π) cm

30 mils

0.03"

0.762mm

 
 
 

1.000mm

 

40 mils

0.04"

1.016mm

 

50 mils

0.05"

1.27mm

 

62 mils

0.062"

1.575mm

 

62.6 mils

0.0626"

1.59mm

 
 
 

1.591mm

1/(2π) cm

 

Most Jandel probes are available with needle spacing anywhere in the range from 20 mils (0.5mm) up to 62.6 mils.

 

 

Common Needle Radii:

 

American

English (Imperial)

Metric

1.6 mil

0.0016"

40µ

2 mil

0.002"

50µ

4 mil

0.004"

100µ

8 mil

0.008"

200µ

10 mil

0.01"

250µ

20 mil

0.02"

500µ

 

Jandel probes are available with tip radii anywhere in the range from 0.5 mils (12.7 microns) up to 20 mils (508 microns).

 

 


Four-Point-Probes is a division of Bridge Technology. To request further information please call Bridge Technology at (480) 988-2256 or send e-mail to Larry Bridge at: sales@bridgetec.com